I. Field of the Invention
The present invention relates to a rain detector for an automotive vehicle.
II. Description of Related Art
Essentially all automotive vehicles sold today include a windshield wiper system. The windshield wiper system typically includes a windshield wiper control circuitry which controls not only the activation of the windshield wipers, but also the speed of the windshield wipers. Furthermore, for intermittent windshield wipers, the control circuit determines the time period of the pause between sequential wipes of the windshield wipers.
In order to control the speed, as well as the pause between wipes for intermittent windshield wipers, a manual control is usually placed in the passenger compartment in a position accessible to the driver of the vehicle. Consequently, in order for the driver to not only activate the windshield wiper system, but also to control the speed of the windshield wipers and/or the amount of the pause between intermittent wipes of the windshield wiper, the driver must make the appropriate adjustment to the wiper control in the passenger compartment. Such adjustments, however, are distracting to the driver and can even result in a safety hazard for the driver and vehicle.
In order to eliminate the distraction of the driver which occurs during manual adjustment of the windshield wiper control, there have been previously known automatic windshield wiper systems. These automatic windshield wiper systems sensed the amount of rain on the windshield and then activated the windshield wiper system as required to clear the rain from the windshield. These previously known rain detector systems typically utilized optical processing techniques to detect the presence and density of raindrops on a selected portion of the windshield. While these previously known systems have operated satisfactorily, the prior systems require a fairly high degree of computational capability which not only results in increased cost for the rain detector system, but also power consumption by the rain detector. Consequently, these previously known rain detector systems for automotive vehicles have not enjoyed widespread acceptance, particularly for medium priced and economy priced vehicles.